This invention relates generally to the art of printing machines, and more particularly to a new and improved inkcup assembly and drive mechanism for a printing machine.
One area of use of the present invention is in a pad-type printing machine, although the principles of the present invention can be variously applied. In a basic pad-type printing machine, a printing plate or cliche has an operative surface provided with an image to which ink is applied for subsequent transfer of the inked image to an object to be printed. Ink is applied to the image by an inkcup assembly which is moved back and forth along the operative surface of the printing plate into and out of operative registry with the image. The inkcup assembly includes a hollow body containing a supply of ink and having an end face which is pressed by biasing means such as a spring against the operative surface of the printing plate. In synchronism with the afore-mentioned movement of the inkcup assembly, a pad is moved into registry with the inked image and pressed thereon to pick up the inked image and then moved into position for pressing the inked image onto the object to be printed.
In machines of the foregoing type heretofore available, the biasing means or spring for the inkcup assembly is part of the printing machine, and this adds difficulty and complexity to maintenance operations performed on the inkcup assembly. Furthermore, the biasing means or spring can apply undesirable forces to the machine frame or other components.
In machines of the foregoing type, it is desired to provide the above-described movements of the inkcup assembly and the pad as fast as possible to achieve the shortest possible printing time cycle to maximize productivity. However, increased speed of the inkcup assembly and pad can cause undesirable machine vibration and jamming of components thereof with resultant rapid wear.
It would, therefore, be highly desirable to provide, in a printing machine of the foregoing type, an inkcup assembly which can be removed easily manually from the machine in a sealed, self-contained condition and in which the biasing means or spring thereof does not apply any force to the remainder of the machine. It also would be highly desirable to provide, in a printing machine of the foregoing type, motive means for moving the inkcup assembly and motive means for moving the pad, both of which provide movement as fast as possible wherein the acceleration is as smooth as possible.